Development of Advanced Microclimate and Urban Energy Analysis Modeling Environment and Its Validation by Wide Area Sensor Networks and Remote Sensing for Future Adaptation of Urban Infrastructure

Description

This project will develop an appropriate framework for monitoring, modeling, and ultimately manipulating the urban microclimate for efficient adaptation of future urban infrastructure. The work combines aspects of assimilation of high-resolution data and advanced modeling of the intricate relationship between urban microclimate and urban form. The data will come from remote and terrestrial wide-area sensor networks while the urban microclimate is expressed through phenomena such as the urban heat island effect, climate change, local wind patterns and solar shading.

The objective of the research is to develop an urban sensing and modeling system that will support:

the preparation and assessment of policy and regulatory measures concerning the urban thermal environment;

the simulation-aided design of urban neighborhoods to account for the coupled interactions of buildings and their environment.

The work is novel and useful for two reasons: First, the proposed simulation environment (umi) will be accessible to planners, developers and architects in their day-to-day professional work. Second, the proposed work will include data assimilation methods to make use of information gathered by the proposed sensor networks. This two way process is unique because to date models are developed with a snapshot of urban conditions and are rarely updated to recognize ongoing urban development.

Relevance

Abu Dhabi is a desert city with extremely hot and humid summer months. On the other hand, the city is on an island with a very long coastline. Sandstorms occur frequently during the summer months and in general the amount of aerosols in the atmosphere is high. The relatively cooler season is between November and March, during which time there are occurrences of fog. Massive reforestation programs have substantially contributed to the increase of green areas in and around Abu Dhabi while rapid urban development has also taken place. With such a varying landscape, the city represents an intense microclimate scenario. Monitoring temperature and thermal comfort there will lead to increased understanding of the Abu Dhabi urban environment and will contribute to future urban planning efforts.

By arranging urban form—streets and parks, building heights and juxtaposition, street canyon width and orientation, surface albedos and spectral properties—to improve outdoor thermal comfort, the number of summer days in which walkable conditions exist will be increased with a corresponding reduction in vehicle miles. For longer trips, improved comfort will also shift passenger miles from personal vehicles to public transit. Heat (and humidity) rejection by building and vehicle HVAC systems increases local temperatures resulting in further increases in cooling and dehumidification loads. Conversely, reductions in vehicle use and air-conditioning loads improve local thermal conditions leading to further reductions in vehicle and air-conditioning use. These consequences of the urban microclimate suggest that urban form, albedo, and landscaping have a direct impact on HVAC and transportation energy use as well as on thermal comfort. The effect on thermal comfort is amplified via behavior change, so as to go beyond the direct impacts.

The possibility of reducing peak daily cooling loads more than average daily cooling loads is also relevant because the continuing rapid growth in electricity generation and distribution capacity is a major concern of the Abu Dhabi government.